Crankshaft grinding machine



Sept. 29, 1942.

F; E. JOHNSON GRANKSHAFT GRINDING MACHINE Filed Nov. 5, 1941 5 Sheets-Sheet 1 Q ww% F RANKL/N E. JOHNSON Sept. 29, 1942. F. E. JOHNSON CRANKSHAFT GRINDING MACHINE 5 Sheets-Sheet '2 Filed Nov. 5, 1941 QN E Sept. 29, 1942. F. E. JOHNSON CRANKSHAFT GRINDING MACHINE Filed Nov. 5 1941 5 Sheeis-Sheet 3 Sept- 1942- F. E. JOHNSON 2,297,654

CRANKSHAFT GRINDING MACHINE Filed Nov. 5, 1941 5 Sheets-Sheet 4 F RANKL. IN E dar-warm p 1942- F. E. JOHNSON 2,297,654

CRANKSHFT GRIND ING MACHINE Filed Nov. 5'===1941 5 Sheets-Sheet 5 FRANKL IN E.'JLI7HNSUN Patented Sept. 29, 1942 UNE'EEB S'E'fa FTEENT FFECE CRANKSHAF'I' GEINDENG MACHINE Franklin E. Johnson, Worcester, Ma.s5., assignor to N olton Company, Worcester, Mass., a corporatien of Massaohusetts 12 Claims.

The invention relates to grinding machines and more particularl to a double Werk head type multiple wheel crankshaft grinding machine.

One object of the invention is 130 provicle a multiple wheel crankshaft grinding machine in whi-ch a pair of spaced grinding wheels are arranged simultaneously ancl successively to grind pairs of spaced alignea crankpins on a crankshaft Another object of the invention is to provicle a multiple wheel grinding maohine in which a transversely rnovable wheel slide serves as a support for a pair of longitudinally movable grinding wheel heads which are arranged for a longitudinal indexing movement; simultaneously to position the grinding wheels suocessively into operative relation With spaced pairs of alignecl pins on a orankshaft. A further object of the invention is to p1ovide a multiple wheel grind:- ing machine in which an electrically controlled fluid pressure interlock is provided between the grinding wheel feecling mechanism and the grinding Wheel traversing o1 indexing mechanisrn.

Another object of the invention is to provide a fiuid pressure interlock between the longitudinal grinding wheel traversing or indexing mechanism and the grinding wheel feeding mechanism which is arranged so that when the index control valve is shifted to initiate an indexing movement of one r both of the grinding wheels, the grinding wheel feed control valve is automatically shiftecl to move the grinding wheel slide rearwardly to an inoperative position before the grincling wheel indexes lon tudinally. A further object 01 the invention is to provide an electrically -controlled interlock which is arranged so that a Wheel feeding movement cannot be initiated until both of the grinding wheels are indexed into corresponding aligned positions relative to the crankpins to be ground. Other objects Will be in part obvious or in part pointed out hereinafter.

The inventiou accordingly consists in the features o'f construction, oombinations of elements, and arrangements of parts, as will be exemplifiecl in the structure to be hereinafter described, and the scope Qf the application of whioh will be indicated in the following claims.

In the accompanying drawings in Whi-Ch is shown one of many possible embodiments of the mechanical features of the invention,

Fig. 1 is a front elevation of the improved crankshaft grinding machine;

Fig. 2 is a right-hand elevation, on an enlarged scale, of the crankshaft grinding machine shown in Fig. 1;

Fig. 3 is a vertical sectional view, on a reducecl scale, taken approximately on the line 33 of Fig. 2;

Fig. 4 is an electrical wiring and hydraulic diagram of a portion of the control for the machine, showing the controls for the longitudinal indexing movement ()f the grinding vvheels;

Fig. 5 is an electrical wiring and hydraulio diagram of the remaining controls for the machine which supplements Fig. 4 and shows the hydraulic controls for the grinding wheel feed, steadyrest and work clamping mechanism together with the electric work stop control;

Fig. 6 is a fragmentary sectional view, on an (enlarged scale, taken approximately cn the line 6 of Fig. 1, showing the connection between the main control lever and the valve stem;

Fig. 7 is a fragmentary cro-ss sectional view, on an enlarged scale, taken on the line l'l of Fig. 1;

Fig. 8 is a longitudinal horizontal sectional view, on an enlarged sc'ale, taken approximately on the line 88 of Fig. l, showing a portion of the grincling whel feeding mechanism;

Fig. 9 is a fragmentary vertical seotional view, taken approximately on the line 9-9 of Fig. 2, showing the slideways between the wheel slide and the Wheel head;

Fig. 10 is a fraginentary cross sectional view, on an enlarged scale, taken approximately on the line ll Of Fig. 1, showing a section through the steaclyrest and its actuating mechanism;

11 is a fragmentary horizontal sectional view, on an enlarged scale, taken approximately on the line HH of Fig. 2;

Fig. 12 is a rear elevation of the main control valve, showing the fluicl pressure interlock mechanism shown in rear elevation;

Fig, 13 is a fragmentary end elevation, taken on the line I3l of Fig. 3;

Fig. 14 is a fragmentary sectional view through the end thrust andradial bearing support for the right-hancl grinding wheel;

Fig. 15 is a fragmentary sectional view, on an enlarged scale, taken approximately on the line fl5l5 of Fig. 3, through the coupling connecting the two aligneol grinding wheel drive shafts or spindles; and

Fig. 16 is a fragmentary vertical cross sectional view, on an enlarged s-cale, taken approximately on the line Il6 of Fig. 3, through a portion of the grinding wheel longitudinal indexing control mechanism.

A double work head type multiple wheel crankshaft grinding machine has been illustrated in the drawings comprising a base 20 which serves as a support for a, pair f spaced aligned work heads 2l and 22. The WOIk heads 2I and 22 serve as supports f0r a pair 0f spring actuated hydraulically released pot chucks 23 and 24 which are arranged in opposed relationship With each other and are arranged to rotate about a. common axis. The pot chucks 23 and 24 are arranged to support and clamp the opposite ends 0f a crankshaft 25 for a rotary motion during a grinding Operation. The supporting spindles therefor have not been illustrated in detail since these features are not considered to be a part cf the present invention. These pot chucks together with their supporting spindles are substantially the same as those disclosed in the prior U. S. Patent to Herbert A Silven and Albert G. Helden, N0. 183'7342 dated December 22 1931, and the patent to Herbert A. Silven, N0. 2,151,- 666 dated March 21, 1939, to which reference may be had for details cf disclosure not contained herein. The work clamping jaws on each of the pot chucks 23 and 24 are actuated by a spring pressure mechanism substantially the same as that shown in the above-mentioned prior patents. The clamping jaws are released by a hydraulic mechanism comprising a hydraulic cylinder 26 which is provided with a slidably mounted piston 21. A piston r0d 28 passes through the work head 2! and is arranged to release the clamping jaw, after a grinding operation has been com pleted, in a manner substantia1ly the same as that shown in the above-mentioned prior patents.

When it is desired to release the clamping jaw of the pot chuck 23, fluid under pressure is admitted through the pipe 29 into a. cylinder chamher 30 to cause the piston 21 to move toward the left (Fig. Similarly, a hydraulic cylinder 31 is mounted on the right-hand end 013 the machine and contains a slidably mounted piston 32 which is connected by means of a piston rod 33 to actua-te the cla-mping jaw 0f the pot chuck 24 so as 110 release the same when fluid under pressure is admitted through a pipe 34 into a cylinder chamber 35 to cause the piston 32 and the piston rod 33 to move toward the right (Fig. 5).

Werk drive A driving mechanism is provided synchronously to rotate the pot chucks 23 and 24. This mechanism may comprise an electric motor 40 which is provided with a multiV-groove pulley 4-I. The p-ul1ey 41 is connected by multiple V- belts 42 with a multi-V-groove pulley 43 which is mounted on one end of a rotatable shaft 44. The shaft 44 (Figs. 1 and 2) is rotatably journalled in bearings (n0t shown) in the base 20. A sprocket 45 is mounted 011 the other end of the shaft 45 and is connected by means of a 1ink chain 46 with a sprocket 41 which is mounted on a rotatable shaft 48 which is journalled in suitable bearings (not shown) within the base 20. The shaft 48 is provided at its opposite ends with sprockets 49 and 50. The sprockets 49 and 50 are connected by link chains 5I und. 52, respectively, with sprockets 53 and. 54 which are operatively connected synchronously to rotate the pot chucks 23 and 24, respective1y, to rotate the crankshaft 25 to be ground. This driving mechanism has not been illustrated in minute detail since this mechanisrn is identical With that shown in the prior U. S. Patent to Herbert A.

Silven, N0. 2,151666 dated. March 21, 1939, to which reference may be had. for details of disclosure not contained herein. The upper surface of the base 20 is provided With a longitudinally extending dovetailed slideway 55 which mates with corresponclingly shaped ways formed 0n the under side of the W0rk heads 21 and 22. The work heads 21 and 22 may be clamped in adjusted position on the slideway 55, and may be adjusted longitudinally along the s1ideway 55 to facilitate setting up the machine for grinding grankshafts cf diflerent lengths.

Manual grinding wheel feed In order that pairs of aligned crankpins on a crankshaft may be simultaneously and successive1y ground, a -pair of transversely movable rotatable grinding wheels 56 and 57 are provided for simultaneously grinding a pair of aligned crankpins 58 ancl 59. The grinding Wheels 56 and 57 are rotatably and longitudinally supported on a transversely movable wheel slide 60 which is arranged to move transversely relative to the base 26 on a pair of spacecl fiat ways 64 and 62 and an intermediate V-shaped guiding way 63 formed on the upper surface of the base 20. The slideways GI, 62 and 63 mate With correspondingly shapecl ways formed on the under side of the wheel slide 60.

A wheel feeding mechanism is provided for moving the wheel slide 60 transversely simultaneously to feed the grinding wheels 56 and 51 toward or from the crankshaft 25 to be ground. This feeding mechanism may comprise a half nut 65 depending from the under sicle of the wheel slide 60 which meshes With or engages a rotatable cross feed screw 66. The cross feed screw 66 is journalled in a bearing 61 which is fixed relative to the base 20. The rear end of the feed screw is journalled in a slidably mounted sleeve 68.

The feed screw 66 may be manually rotated to produce a manual transverse feeding movement of the wheel s1ide 60 either to produce a grinding feed or for use in setting up the machine for a grinding operation. A rotatable feed wheel 10 is rotatably supported on a stud H journalled in bearings 12 and 13 mounted on the front Qf the machine base 20. The band wheel 10 is provided With gear teeth 14 which mesh With a gear I5. The gear 15 is preferably formed integral with a rotatable sleeve 16 havring a sleeve bearing 11 which rotatably supports the s1eeve 16 and gear 15 on a portion of the rotatable drive shaft 48. The sleeve 16 is held against endwise movement on the shaft 48 by a pair of collars 78 anal 19 which are fixedly mounted with respect to the drive shaft 48. A spiral gear 80 is also formed integral with the sleeve 16 and meshes With a spiral gear 8I. The spiral gear 81 is rotatably journalled in a bearing 82 which is fixedly mounted with respect to the base 20. The spiral gear 8I and a hub 83 formed integral therewith are slidably keyed to the forvvard reduced. end portion 84 of the feed screw 66. It will be readily apparent from the foregoing disolosure that rotary motion of the manually operable feed wheel 10 will be transmitted through the gear mechanism above described to impart a rotary motion to the feed screw 66 to cause a transverse feeding movement of the wheel slide 60 and the pair of spaced grinding wheels 56 and 5T.

Bush pot anal positive stop In order to move the wheel slide 60 transversely to move the grinding wheels 56 and 51 transversely for a considerable distance, thatis, in moving the grinding wheels to and from an operative grinding position and also to impart a power feeding, a hydraulically operated mechanism is provided comprising a cylinder 85 which is supported in fixed relation with the base 20. The cylinder 85 contains a slidably mounted piston 86 which is connected to a piston rod 8'I. The piston rod 87 extends in both directions from the piston 85 and is connected at its lower end (Fig. 5) to the slidably mounted s1eeve 68. It will be readily apparent from the foregoing disclosure thafi if fluid under pressure is admitted through a pipe 88 into a. cylinder chamher 89, the piston 86 will be moved downvvardly (Fig. 2) to impart a transverse feecling movement through the feed screw 55 and half nuo 65 to move the wheel slide 60 transversely to feed the grinding vvhee1s 55 and 57 toward the crankshaft 25 I;o be ground. During this forward feeding movement of the wheel slide GI), fiuid is exhausted from a cylinder chamber 95, throu2h a pipe 9I.

A fiuid pressure systern is provided for comveying fiuid under pressure to the cylinder 85, comprising a motor driven fluid pump 95 which draws fluid through a pipe 96 from a reservoir 91 and forces fiuid under pressure through a pipe 98, to a manually operable rnain control valve 99. A relief va1ve 155 is connected to the pipe 1ine 98 and serves to exhaust exoess fiuid under pressure 1nto the reservoir 9'I. The mein coutrol valve 95 is a piston type va1ve comprising a valve stem I5I having a plurality of valve pistons III2, I53, IM and I05 formed integrally therewith. In the position of the parts shown in F1'g. 5, fiuid under pressure within the pipe 98 passes into a valve chamber located between the va1ve pistons I3 and I M and passes out through the pipe 91 into the cy1inder chamber 95 to move and. hold the piston 85 in its rearward position so as to move the grinding vvheels 55 end 51 rearwardly to an inoperative position. During this movement fiuid under pressure exhaust from the cylinder chamber 83, through the pipe 83, into a valve chamber locaued betvveen the va1ve pistons I52 and I3, and out through a variable throttle va1ve 185 and a pipe III'I, into the reservoir 91.

A manually operable control lever I98 is pivotally mounted on a stud I59 which is in turn supported by a bracket II!) fastened to the freut of the machine base 25. The valve stem II3I is provided with a transversely extending pin III the opposite ends of which ride in an elongated s1ot II2 formed in the control lever I65.

When it is desired to feed the grinding wheels transversely toward the crankshaft 25 to be ground the control lever H38 is swung in a counterclockvvise direction (Fig. 5) so that fiuid under pressure passing through the pipe 58 into the valve chamber located betvveen oho va1ve pistons IE3 and I 04 passes outwardly through the pipe 85 into the cylinoler chamber 55 t cause the piston 85 to move toward the 1eft (Fig. 2) to impart a corresponding movement to the feed screw 66 and the wheel s1ide 55 which in turn transmits a corresponding transverse movement to the spaced rotatable grinding wheels 55 and 5'I.

In order 130 obtain a slow uniform grinding feed of the grinding wheels 55 and 5'I, a dash pot feed control mechanism is provided comprising a casing II5 which is mounted on the rear end of the cylinder 85. The dash pot casfing I I5 contains a. pair of spaced s1idably mounted dash pot pistons II 6 and II'I. A slidably mounted sleeve H8 15 supported on the rear portion 0f the piston rod 81. The sleeve H8 has a fianged portion II9 Which is fixedly secured thereto. The fiange II9 is arranged to engage the rear end faces of the dash pot pistons II6 and I II, respectively. A stop screw I20 engages the fiange II9 and thereby serves to limit the rearward movement of the dash pot pistons II6 and I IT uncler the influence of compression springs I2I and l22.

The rapid forward feeding movement of the grinding wheels 55 and 57 With the wheel slide 65 continues until an adjustable co1lar l23 on a threade-d p0rtion I24 of the piston rod 87 engages the rear end of the sleeve II8 (Fig. 2). Continued forward movement of the piston rod 81 moves the sleeve II3 anti the fiange II9 into engagement Wih ends of the dash pot pistons II 5 and II'I. The rapid approaching or feeding movement of the grinding wheels 55 and 51 toward ehe crankshaft 25, as produced by the piston 85, is reduced to a slower predetermined grinding feed due to the fact that fiuid confined within the dash pots is interconnected by a passage I25 to exhaust fiuid under pressure through a passage I25, a needle valve I2'I, and through a pipe I28 into a fluid reservoir I29. By adjusting the aperture 0f the needle valve I2'I and the throttle valve I3EI a desired and predetermined infeeding movement of the grinding vvheels 56 and 51 and their supporting vvheel s1ide 60 may be obtained. The dash pot feeding mechanism above described is substantially identical With that shown in the prior U. S. patent to Bernhard H. Goehring, N0. 2151660 dated March 21 1939, to which reference may be had fr details of disclosure not contained herein.

Gri1zding w-heel indem control The grinding wheels 56 and 51 are arranged so that they may be positively and synohronously rotated during a grinding operation. The grinding wheels 56 anal 51 are also arranged so that they may be indexed longitudinally, successively to position the wheels opposite pairs of spaced aligned crankpins on the crankshaft 25 to grind the Same.

The grinding whee1 55 is supported on a rotatab1e wheel spind1e I35 (Fig. 3) which is journalled in bearings I36 and I3'I. The bearings I3Ii and I 3'! are supported in a longitudinally sdable wheel head I38 which is arranged to slide longitudinally relative to I;he Wheel slide 50. A fiuid pressure operated mechanism is provided for indexing the whee1 head I38 longitudinally position the grinding wheel 56 successively in operative position With the sucoessive crankpins to be ground.

A hydraulic cylinder I35 is fixedly mounted an the wheel slide 55 (Fig. 3). A piston Mi2 is slidably supported within the cylinder I39 and is fixedly mounted on a piston rod I4I. The rightband end of I;he piston r0d IM is fixedly comnectecl a bracket I 42 Which is in turn fixedly mounted 130 the wheel head I38. It Will be readily apparent from the foregoing disclosure that when fluid is admitteo'l through a pipe M3, into a cylinder chamber IM, the piston H55 together with the piston rod I4I, the bracket H32, and the wheel head I38 together with the grind- 1'ng wheel 56 Will be movecl toward the right (Figs. 3 and 4). Similarly, when fiuicl under pressure is admitted through a, pipe 145, into a. cylinder chamber 146, the piston 149 together with the connecting parts Will move the wheel head 138 toward the left. A stop screw 141 is mounted on a bra.cket 148 Which is in turn fixedly supported On the left-hand end of the wheel s1ide (Fig. 3) and serves 120 limit the movement of the piston 145 together with the wheel head 138 in a direction toward the left (Figs. 1 and 3). A pair of collars 149 are adjustably mounted x1 a. threaded portion of the piston rod 141 adjacent 170 its left-hand end (Figs. l, 3 and 4). The collars 149 are arranged to engage the end face of the cylinder 139 and serve 150 limit the movement of the piston 168 and the wheel head 138 toward the right (Figs. l, 3 and 4) precise1y 130 1ocate the grinding wheel 56 for grinding crankpin 58b (Fig. 1).

A plurality of normally open 1imit switches 159, 151 and 152 are arranged in the path of a cam 153 which is mounted on the bracket 142 (Figs. 3 and 4). The switches 155, 151 and 152 are mounted on the wheel slide 611 and serve in a manner 110 be hereinafter described successively 150 stop the wheel head 138 in successive predetermined grinding positions with the grinding wheel 56 located opposite successive crank-1vins on the crankshaft 25 120 be ground.

Similarly, the grinding wheel 51 is supported a1: one end of a rotata.ble wheel spindle 155 which is journalled in bearings 156 and 151 Which are in turn supported in a. longitudinally movable whee1 head 158. The wheel head 158 is slidable longitudinally 011 suitable mating ways on the Whee1 slide 69 to maintain the wheel head 158 in its proper operating position, as shown in Figs. 2 and 9. A fluid pressure mechanism is provided for indexing the wheel head 158 longitudinally comprising a fiuid pressure cylinder 159 which contains a. slidably mounted piston 1611. The piston 155 is connected by means of a. piston rod 161 wi1ah a bracket 162 depending from and fixed1y mounted on the under side 01 the whee1 head 158. When fiuid unde1 pressure is admitted through a. pipe 163 into a cylinder chamber 164, the piston 169 will be moved toward the 1eft (Figs. 1, 3 and 4) t0 position the grinding wheel 51 in respect 1:0 ehe crankpins 130 be ground.

When fiuid under pressure is admitted through a pipe 165 into a. cylinder chamber 166, the piston 169 together with the wheel head 158 Will be traversed or indexed toward the right (Figs. l, 3 and 4). An adjustable stop screw 161 supported in a bracket 168 Whi0h is fixedly mounted on the right-hand end of the wheel s1ide 66 serves to 1imit the movement of the piston 169 a.nd the Wheel head 158 toward the right. A pair 0f spanner wrench collars 169 are adjustably mounted on a threaded portion a1: the right-hand end of the piston rod 161. The collars 169 are arranged to engage the right-hand face 01 the cylinder cover 0f the cylinder 159 and serve 10 1imit the movement 0f the piston 166 and the wheel head 158 in a direction toward the left (Figs. 1, 3 and 4) precisely to locate the grinding whee1 51 for grinding a crankpin 59b (Fig. 1). A plurality of normally open 1imit switches 116, 111 and 112 mounted on the wheel s1ide 65 are arranged in the path of a cam 113 mounted on the bracket- 162 (Figs. 3, 4 and 16) and serve in a manner 170 be hereinafter described to stop and position the grinding wheel 51 and wheel hea.d 158 in the desired and predetermined positions for grinding successive crankpins 0n the crankshaft 25 being ground.

Grinding wheel drz've A motor driven mechanism is provided for synchronously driving the rotatable grinding whee1s 56 and 51 together With their respective wheel spindles 135 and 155. The wheel spindles 135 and 155 are hollow spindles and contain slidab1y keyed driving shafts 115 and 116. The 0111:- er ends of ehe shafts 115 and 116 are supported in anti-friction bearings contained within the housings 111 and 118 mounted and clamped to the Whee1 slide 611. The inner ends of the drive shafts 115 and 116 are connected by a. coupling 119 so thab the driving spindles or shafts 115 and 116 may be separated when it is desired to mount a. grinding wheel 011 either of the wheel spindles 135 and 155. An electric motor 185 is mounted 0x1 an adjustably positioned motor support 181 which is slidably supported 0n a portion of the wheel s1ide 611. A screw 182 and a nut 183 are interposed between the b-racket mounted on the whee1 s1ide 611 (Fig. 2) and the motor support 181 and serve to facilitate transverse adjustment of the electric motor 186 to tension the driving V-belts as desired. A motor shaft 184 of the electric motor 185 supports a multi-V-groove pulley 185 which is connected by multiple V-belts 186 with a multiple V-groove pulley 181 mounted on the right-hand end of the drive shaft 116. It Will be readily apparent from the foregoing disclosure that when the electric motor 186 is startec1 rotating by actuating the push button switch 138 on the base 211, a rotary motion Will be transmitted through the pulley 185 driving the V- belts 186 and pulley 181 rotate the shaft 116 which in turn 10ta-tes the whee1 spindle 155 and the grinding whee1 51. Due to the coupling 119, rotation of the spind1e Will be transmitted through the shaft 115 to impart a rotary motion t0 the wheel spind1e 135, synchronously to rotate the grinding wheel 56 with the grinding wheel 51.

Sparlc splz'tiz'ng rlevice 'Ihe grinding wheels 56 and 51 together with their supporting spindles anc1 155, respective1y, are arranged f0r an axia1 adjustment so the1t as the grinding wheels are fed toward a pair of crankpins to be ground the Wheels 56 and 51 may be moved axially to split 1;he spark or equa1- ize the side grinding on opposite corners of the peripheral faces of the grinding wheels. A. spind1e adjusting mechanism 196 15 provided for axially Inoving the spindle 135 and grinding wheel 56 which is controlled by means of a manually operable lever 191. Similarly, a spindle adjusting mechanism 192 is provided for axially adjusting the spind1e and the grinding whee1 51 which is actuatea by a manua1ly operable 1ever 193. These spindle adjusting 01 spark sp1itting mechanisms have n0t been illustrated in detail in the present application sinc they are not considered 130 be a part of 1Zhe present invention. These mechanisms are substantially ident1cal 130 that shown in the prior U. S. patent 120 Herbert A. Si1van, N0. 2,151,666 dated. March 21, 1939 Which reference may be had Zar details of disc1osure not contained herein.

S teadyrests 113 is desirable to support the pair 0f spaced crankpins beim; ground during he grinding operation. A pair of spaced steadyrests 194 and 195 are provided. The steadyrests 195 and 195 are preferably of a hydraulically operated type such as, f0r example, that shown in the prior U. S. patent 1&0 Herbert A. Silva.n N0. 2053878 dated September 8, 1.936, to which referen'cie may be had for details of disclosure not eontained herein. The steadyrest I 92 comprises a vertically movable slide 155 which serves as a support for a transversely movable steadyrest shoe carrying member 191. The slide 195 15 arranged to slide vertically on a steadyrest framg 198 which is provided with suitable mating slidelvays. A fluid pressure cylinder 199 is formed integral with the steadyrest frame 158. The cylinder 199 contains a slidably mounted piston 250 which i-s oonncted by a piston rod 2131 with a bracket 222 whioh is formezd integral with or fixedly mountecl on the 1ower end of the vertical slide 196.

When fluid under pressure is admitted through a pipe 223 which is connected to the pipe 91, into a cy1inder charnber 262 to cause a downward movernent f the piston 21111, the slide 155 together With the shoe carrying slide 197 is moved down wardly to an inoperative position to iacilitate longitudinal positioning by the Wheel head 138. Similarly, When fiuid under pressure 15 admitted through a pipe 255 into a cylinder chaniber 256, the piston 2013 together with th piston rod 201 and the slide 195 together With the shoe supporting member 191 are rnoved Vertically to an operative position With the steadyrest shoe in operative engagement with the crankpin to be grounol. A manually operable nut and screw mechanism 287 (Fig. l) is provicled to adjust the shoecarry- 111g slicle 187 transversely either toward or from the crankpin to be ground.

Simi1arly, the steadYrest 195 is Provided with a vertically movable slide 210 which is arranged to be moved vertically relative to a steady=rest frame 211. A fiuid pressure cylinder 212 is formed. integral With the steaclyrest frame 211 and contains a slidably mountea piston 213. The piston 213 i conne0ted 1oy a piston roci 212with a bracket 215 which is integ'ral with the lower end of the vertically movable slid 21E3. The sli'de 212 Supports a transversely movable shoe carrying member 215 which is providecl at it inner end With a work engaging shoe 217 (Fig. 2). A Inanually operable nut and screw feeding mechahism 218 is providea for manualhr adjnstin'g the position of the shoe carrying slicle 216 and theWork engaging shoe 212 transversely into 01 away fr0m operative engagement with the crankrbiri to" be ground. When fluid uncler pressure isadmitted through a pipe 219'W1'11C1'1 is connected t0 the pipe 9 1, into a cylinder chamber 220; the piston 213 together with the slicle 212 and the shoe carrying slide 215 are moved downwardly to an inoperative position to facilitate longitudinal adjustment by the wheel head 158, 0f the steadi'res't 125 during the grinoling of successive crankpins on a crankshaft. Similarly, When fluid is admitted through a pip 221 into a cylinder chambei 222 the piston 213 together with the piston rocl 214, the s1ide 218, the shoe carrying slide 216, and the work stleadyrest shoe 217 are mov eclupwardly into an operative position. During the grinding operation the work steadying shoes of the steadyrests 192 and 125 may be manually adjusted toward and from the surfat:e of'the vv'o'rk piece being ground and maintained in operative contact therewith during a grinding' Operation with the desired pressure by manual inariipiila tion of the nut and screw actuating mechanisms 252 and21 respectively.

Werk rotation control In a crankshaft grinding machine of the type illustrated, it is desirableto stop the pot chucks 23 and 24 in an upright position to facilitate the 10ading operation. A motor brake switch 225 is provided for stopping the electric motor 413 at the desired and predetermined time to stop the pot chucks 23 and 24 in predeterxnined upright positions. The motor brake switch 225 is controlled by a cam 226 which is mounted to rotate the work supporting spindle (Fig. 5) supporting the pot chuck 23 and a normally closed trip switch 221 mounted 011 a frarrl fixed to the base 211.

When the main control valve 99 is shifted to its rearward position, a cam surface on a crossshaped head 228 mounted on the valve stem 121 0Dells a normally closed limit switch 229 to break the circuit. When the circuit through the 1imit switch 229 is broken, a solenoid 235 on the base 211 is deenergized to release the tension of a spring. This movernent serves to ro ;k a lever 231 to move a slidably mounteol rod 232 so that the roller on the end of the rod 232 rides upon the periphery of the cam 221:. The motor 412 for rotating the work supporting pot chucks 23 and 24 is preferably of a type which is controlled by a magnetic starter reverse relay 233 and a motor brake switch 225 so that the rotation of the motor 411 rnay be stopped in a predetermined position after a grinoling operation has been completed. As shown in the electrical wiring diagrarn (Fig. 5), the motor 55 is controlled by a magnetic Starter reverse relay 233 which controls the forward and reverse fields of the motor 40.

When the solenoid 2311 is deenergized, the roller mounted on the rod 232 is move'd' by the spring actuatecl lever 231 into contact With the cam 225. The movement of the roiier on the rod 232 into operative contact With the cam 225 serves to open a normally closed trip sWitch 221 which opens the circuit and cuts the power from the power field 01 the motor 2a]. This movement serves through the motor brake svvitch 225 actuate a magnetic motor reverse relay 232 which serves instantaneously to reverse the eurrent in the motor 40 and, through the Inotor brake switch 225, to stop the motor 211 so that the pot chucks 23 and 22 are in a predetermined upright loading position.

A safety relay 235 is so connected as to render the power circuit inoperative in case the electric current fails. Uponfailure of the e lectric eurrent supplieol to the driving motor 32, the safety relay 235 opens and before the work rotation can be again started, a make contact reset push button 236 must be pushed to c1ose the circuit. This movement in turn serves to close the safety relay 235 and thereby again to start the rotation of the motor 41). A make contact push button 231 serves as a jogging switch to jog the rotation of the work, if desired. A double pole snap switch 238 serves in one position to permit a Jogging of the work rotation by the push button 237 or in the opposite diriection serves to start the rotation of the motor 410. A double pole snap switch 239 serves in one position to remier the automatic control of the work rotation inoperative to facilitate manual control to permit jogging of the work rotation as desired, and in the position shown in Fig-. 5 serves to ren'der the automatic control of the work rotation operative. By manipulation of the push buttons 236 and 231 and the snap sWitches 258 and 232; the rotation of the WOIk driving motor 15 rnay be readily controlled as desired. A re1ay 225 servs to control the use of the motor brake svvitch 225 by breaking the circuit through one of the contacts in the Starter reverse relay 233 Which controls the. motor reverse relay 234. It is not deemed to be necessary to more fuily describe the Werk rotation and stop control mechanism in the present case sinne this feature is substantially identical With that shown in the prior U. S. patent to Herbert A. Silven, N0. 2,151666 dated March 21, 1939, to which referenoe may be had for details of disclosure not contained herein.

The main control vaive 69 and main control lever 108 are located on the ieft-hand portion of the front of the machine base 20. It is desirable in a machine of this type to be abie to manipulate the contro1s from either end of the machine as occasion requires. A manually operable control va1ve 241 is provided having a valve stem 242 which has a control knob 243 projecting from the front of the machine base 26. The control valve 241 is a baianced piston type vaive which is normally he1d in a central or neutral position by means of a spring 244. Fluid under pressure passing through the pipe 93 enters a centraily located va1ve ohamber 245. When the control knob 243 is moved toward the operator, fiuid entering the valve chamber 245 may pass through a pipe 246 into an end chamber in the main control valve 99 and serves 130 shift the valve stem 161 together With the valve pistons formed thereon toward the front of the machine.

Simi1a.rly if the control knob 243 is moved away from the operator, fiuid under pressure entering the va1ve chamber 245 passes through a pipe 241, into an end chamber 246 in the main control valve 99, to move the valve stem 101 in a direction toward the rear of the machine. It Will be readiiy apparent from the foregoing disclosure that the control va1ve 241 as controllezl by its control knob 243, serves hydraulicaliy to shift the main control vaive 96 in case such a movement is desired when the operator is adjacent to the right-hand end portion of the grinding machine. A pair of throttle valves 249 are provided in the exhaust pipe 101 to be used, if desired, for producing an adjustable controlled s1ow movement of the valve stem 161 of the main control va1ve 99.

Positz'om'ng indexing interloc7c It is desirable to provide a fluid interlock between the grinding wheel feeding mechanism and the longitudinal traversing 01 indexing movement of the grinding wheels 56 and 51. As illustrated in the drawings, an eiectrically contro1led fluid pressure interlock is provided, comprising a grinding wheel locating va1ve 250 Whioh is biased to a leftd1and end position by a compression spring 251. An eiectric solenoid 25 serves when energized to move the vaive 250 120 its right-hand end position (Fig. The pipe 98 passes fiuid under pressure from the pump 95 into a valve chamber 253. When the soienoid 252 is deenergized and the valve 256 is in its leithand end position, fluid under pressure entering the va1ve chamber 253 passes outwardiy through a pipe 254 into an end chamber 255 in the valve 241, to move the valve stem 242 together with the valve pistons formed thereon into its rearward position. In this position fiuid under pressure entering the va1ve chamber 245 in the control va1ve 241 passes outwardly through pipe 241, into the end chamber 243 of the main control valve 99, to hold it in the position shown in Fig. 5. In this position the grinding wheels 56 and 51 are held in a rearward or inoperat-ive position, the steadyrests are he1d in a downwardly or inpot chucks 23 and 24.

operative position, and the work clarnps on the pot chucks 23 and 24 are released.

The limit switches 156, 151, 152 and 116, 111 and 112 are connected in series With each other respectively, and are in turn connected so that when both of the grinding Wheels 56 and 51 are located in any of the predetermined grinding positions opposite the crankpins 5659, 58a59a or 58b59b respectively, the circuit Will be c1osed to energize the solenoid 252 which serves to shift and maintain the valve 250 in the positions indicated in Figs. 4 and 5. In this position either the control knob 243 or the main control lever 106 may be actuated to start a grinding operation, namely, to exhaust fluid from the cy1inder chambers 36 and 33 thus facilitating olamping of the crankshaft 25 in position within the The wheel slide 60 is then fed forward to move the grinding wheels 56 and 51 toward the crankpins 50 and 59 to be ground. The steadyrests 194 and 195 are then automat-ically moved upwardly into operative supporting engagement With the steadyrest shoes in operative supporting engagement With the crankpins 58 and 59. It Will be readily apparent from the foregoing disclosure that When the grinding wheels 56 and 51 are both looated in respective grinding positions and the pairs of normally open 1imit switches 150110, 151111 or 152-112 are closed an infeed of the grinding wheels can be initiated.

A two-way va1ve 255 is provided whereby fluid under pressure may be passed into an end chamher 256 to maintain the valve 250 in a right-hand end position by fiuid under pressure, if desired. A Valve 251 is provided in the pipe 1ine 254 whereby the rate of passage of fluid may be varied to control the speed of movement of the va1ve 241 as desired. The va1ve 251 may also be entirely closed to render the valve 250 imperative, if desired.

Indexing control valves An independent pump 260 is provided for supplying fiuid under pressure for indexing the grinding whee1s 56 and 51. The pump 260 and the pump are preferably in the form of a duplex pump which is driven by an electric motor 261 (Fig. 2) which is controlled. by the push button switch 259 mounted on the front of the machine base 20. The fiuid pump 260 Which draws fiuid through a pipe from the reservoir 91 is arranged convey fluid under pressure through a pipe 262 to a control valve 263 which controls the indexing o1 truing movement of the grinding whee1 56 and to a control valve 264 which contro1s the indexing or truing movement of the grinding wheel 51. A relief valve 265 is connected between the pipe 262 and the reservoir 91 by means of which the pressure in the System may be readily controllwed and by means of which excess fiuid under pressure may be directly exhausted into the reservoir 91. The grinding whee1 indexing control valves 263 and 264 are mounted on the front of the machine base 20 and are both readily accessible from the operators control station.

The index control valves 263 and 264 are balanced piston type valves having valve stems 266 and 261 which are he1d in a central or neutral position by means of spring-pressed detents 268 and 269, respectively. Actuating control knobs 210 and 211 are mounted on the ends of the valve stems 266 and 261, respectively, by means of Which the control va1ves 263 and 264 may b-e readily controlled manually.

The index cont1ol va1ve 253 is arranged 170 couvey fiuid under pressure through the pipe 143 into the cylinder chamber 144 at the right-hand end of the cylinder 139 o1 through the pipe 145 to the cylinder chamber 146 a1: 1;he left-hand end of 1:he cylinder 136. It Will be readily apparent from the foregoing disclosure that the grinding wheel 56 may be indexed in either directi m by manipula1:ion of the control knob 2111. The direction of movement 01 the contro1 knob 215 determines th direction of indexing movement imparted 120 the grinding wheel 55.

Simi1arly, the index contro1 va1ve 264 is canneoted by ehe pipe 163 Which controls the passage of fiuid 130 or from the cylincler chamber 164 a1; 1;he right-hand end f the cylinder 159. The pipe 165 serves 170 pass fiuid under pressure 130 o1 exhaust fiuid from the. cylinder chamber 166 at the left-hand end of the cy1inder 159 (Fig. 4). The direction of movement of the control knob 211 Will determine the direct-ion of the indexing movement impartea to the grinding wheel 51.

A valve 266 is connected in an exhaust pipe 231 to control the exhaus1; cf fiuid from the cylinder 139 passing through the index control valve 263. The valve 286 is a piston type valve which is normally bald in its right-hand end position (Fig. 4) by means 01 a compression spring 282. the position of the valve 236 shown in Fig. 4, fiuid exhausting from the index control valve 263 and cylinder 139 is free so pass unrestricted through an exhaust pipe 233 in1;o the reservoir 61. An electric solenoid 234 is provided for shifting the va1ve 286 toward the rig'ht, which movemen1: serVes 1.0 cut 01T the exhaust 0f fiuid from the cylinder 139 anal serves When energizea to stop the longitudinal indexing movement Qf the grinding wheel 56. An adjustable valve 265 is provided for controlling the exhaust of fiuid from 1;he index control valve 253 as desired for the indexing rate of trave1 of the grinding wheel 56. Also, adjustable throttle valves 286 and 261 are provided for producing a very slow longitudinal movement of the grinding wheel 56 when it is desired 1:0 true the grinding wheel 56.

Similarly, a valve 233 is provided in a pipe line 291 Which exhausts fluid from 1she cylinder 159, through the index control va1ve 264. A spring 292 serveg normally 130 hold the valve 296 in its lef1z-hand end position, in which position fiuid is free to exhaust unres1sricted. through the pipe 293, into the reservoir 91. A solenoid 264 is provided for sh.ifting 1she valve 266 in a direction toward the right (Fig. 4), whioh movement serves cu1; 0ff the exhaust of fiuid through ehe pipe 291 ancl thereby 110 stop the longitudinal indexing movement of the grinding wheel 51. An adjustaole valve 295 in the pipe line 291 serves 150 facilitate regulation of 1;he exhausting fluid from the cy1inder 159 so tha1; the speed of the indexing movement thereof may be readily controlled. Adjustab1e throttle valves 296 and 231 (Fig. 4) are provided 130 facilitate the -contro1 0f exhausting fiuid when the index control valve 264 is actuated so provide a s1ow longitudinal movement of the grinding wheel 51 for a truing operation.

The index control valves 263 and 264, as above described, are arranged to be ind ependently operated 130 independently control 1:he longitudinal indexing or truing movementg of the grinding wheels 56 and 51, respectively. It may be desirab1e to provide an interconnection between the index control va1ves 263 and 264 so that the actuation of either on of 1;he index control valves will simultaneously produce an indexing or truing control of both the grinding Whee1s 56 and 51. A pipe 31311 interconnects the pipe 143 with 1;he pipe 163. A pipe 361 interconnects the pipe 145 with the pipe 165. A valve 302 is provided in the pipe line 366 and a va1ve 363 is provided in the pipe line 3111. If both of the valves 362 and 363 are opened, 13h@ va1ve 216 in the pipe 163 and the valve 211 in the pipe line 165, both ad- J'acent 130 the index oontrol valve 264, are closed to disconnect or render inoperative the index control va1ve 264. It is apparent that it is necessary 130 have the valves 216 and 211 130 shu1: off, othervvise fiuid Will by-pass o1 exhaust directly 120 the reservoir 91 when the index control valve 263 is actuated adn'1it fluid 130 1;he cylinders 139 anal 159 to control the simultaneous indexing er truing of the grinding wheels 56 and 51.

Sirnilarly, if it is desired 1:0 have the index con- 1;r01 vaive 254 independently contro1 the indexing 01" truing movement of the grinding wheels 56 and '51, the valves 362 anal 353 are opened and the valves 216 and 211 remain open. The valve 212 in the pipe line 143 anal the valve 213 in the pip line 145, booh adjacent to the index control valve are closed disconnect or render inoperaizive the index con1zrol va1ve 263. By closing the valves 212 and 213, fiuid under pressure Will not by-pass or exhaust directly into the reservoir 31 when the index control valve 264 is actuaed to admit fluid the cylinders 139 and 159 10 control the simultaneous indexing or truing movement of the grinding wheels 56 and 51. If it .1s desired independently to contro1 the longitudinal indexing of the wheels 56 and 51, the valves 332 anal 363 are closed and the valves 212, 213, 216 and 211 are opened, so as to provide an inependent indexing or truing control for each of the grinding whee1s 55 anal 51.

Interloclc A fluio1 pressure interlock is provided between she grinc1ing wheel longitudinal indexing mecha- Isin and the wheel feed.ing mechanism so that if either -of the index control valves 263 0r 264 is movod during a grinding wheel feeding operation,

the wheel s1ide 611 Will be moved to a rearward or inoperative position before a longitudinally movable indexing movement may take p1ace. A plurality of small fiuid pressure cylinders 3115, 366, 361 and 353 are fixed1y mounted or formed integral with the casing 01 the main control valve 55. 'lhese cylinders contain pistons 3119, 316, 311 and 312 which ar fixedly connected 130 the crossshaped plate 226 which is fixedly mounted 170 the rear end of the valve stem 1111. A pipe 313 is connected between the pipe line ano1 the cylinder A pipe 314 is connected be1;ween the pipe line 143 and the cylinder 306. A pipe 315 is C011- nected between the pipe line 351, which is connected 130 1:he pipe 165, and the cylinder 3131. A pipe 316 is connected between the pipe line 3111], which i.s connected 1:0 the pipe 163, and the cylinder 365. I1; Will be readily apparen1: that if either the inc1ex control valves 263 or 264 are moved from their central er neutral positions 130 nass fluid through any of the pipe 143, 145, 163 anal 165, fluid Will be admitted 110 one of the cy1- inders 3115, 366, 331 er 358 cause a rearward movement of the valve stem 101 of the main control valve 99 to admit fluid 130 move 1;he grinding wheels 56 and 51 1:0 a rearward. position. The cylinders 365, 3116, 301 and 368 being of compara.tively small diameter and requiring less powe'r to shift the main control va1ve 99 than to index the massive wheel heads, the feed control valve Will be shifted first 150 move the grinding wheels 56 and 51 to a rearward positon before any longitudinal indexing movement may be imparted to either the wheel 56 o1 the wheel 51. It will be readily apparent from the foregoing that a definite interlock is provided between the longitudinal indexing movement for the grinding wheels 56 and 51 and the transverse movement thereof.

By-pass valve interlock A further interlock is provided between the wheel feeding and the wheel indexing movements, comprising a fiuid actuated by-pass valve 320. As shown in Fig. 5, fiuid under pressure passing through the pipe 91 to the wheel feed cylinder 85 also nasses through the pipe 219 and a. pipe 321 into an end chamber 322. Fluid within the opposite end chamber, sirnilar to the chamber 322, during this movement exhausts through a throttle va1ve 324 and a pipe 325 which connects with the pipe 88. The throttle va1ve 324 serves to regulate the speed of movement of the piston 323 as fiuid under pressure is applied to either end chamber of the by-pass va1ve 320. In Fig. 4, if a valve 214 is closed in a pipe 215 shunted or by-passed around the by-pass va1ve 320, and the index contro1 valve 263 is moved toward the 1eft, fiuid under pressure passing through the pipe 145 passes into a valve chamber 321 in the by-pass va1ve 320 and out through the other section of the pipe 145 which is connected to the right-hand end cylinder chamber 146 of the cylinder 139.

Similarly, if the index control valve 264 is moved toward the right (Fig. 4) to admit fluid through the pipe 165, this fluid passes through a va1ve chamber 329, out through the other section of the pipe 164, and into the left-hand end chamher 166 of the cylinder 159. If the by-pass va1ve 320 is rendered inoperative, the throttle valve 324 is closed so that the piston 323, mounted in a horizontal position, will remain in the position shown in Fig, 4. In this case the operator must move the grinding wheels 56 and 51 rearwardly before they are indexed.

T shorten the pipe 1ines between the index control va1ves 263 and 264 the piston 323 of the by-pass va1ve 320 may be locked in the reverse position to that shown in Fig. 4 by shutting off the throttle va1ve 324 and blocking the exhaust of fiuid from the end chamber. In this position the by-pasg valve 326 is inoperative and it is, therefore, necessary to open the valve 214 in the pipe 1ine 215 and a va1ve 216 in a pipe 219 in order to index the grinding wheels 56 and 51. If the by-pass va1ve 320 is rendered operative, fluid must pass through the pipe 325 and va1ve 324 before the grinding wheels 56 and 51 may be moved in either direction. For indexing or truing, the adjustrnent of the throttle valve 324 a1lows the main control va1ve 99 to be moved to its rearward position before indexing takes p1ace.

When the main control va1ve is shifted to cause an infeeding movement of the grinding wheels, fluid under pressure is passed through the pipe 88 to initiate a forward feeding movement of the grinding wheels. At the same time, f1uid under pressure passes through the pipe 325 into the end chamber to shift the piston 323 of the by-pass va1ve 320 to its opposite end position from that v illustrated in Figs. 4 and 5, which movement serves to prevent fluid under pressure rom passing through the by-pass valve 320, thus preventing a longitudinal indexing movement 0f either of the grinding whee1s 56 and 51.

Electrz'cally controlled stop The stop sorews 141 and 151 determine the positions of the grinding wheels 56 and 51 for grinding the crankpins 58 and 59 (Fig. l) Simi- 1ar1y, the set of coliarg 149 and 169 lirnit and. position the grinding wheels 56 and 51 as they are indexed toward each other to 1ocate the grinding wheels for grinding the crankpins 58b and 59b, respectively. In order t0 locate the grinding wheels for grinding the crankpins 58a and 59a, an electrical control mechanism is provided comprising a pair of 1imit switches 335 and 336 which are normally open and are mounted on the wheel s1ide 60. A pair cf adjustable cams 331 and 338 are carried by the brackets 142 and 162, respectively. When the grinding whee]s 56 and. 51 are indexed toward each other, a they approach positions opposite the crankpins 58a and 59a, the carns 331 and 331 which move in the path of the actuating plungers of the limit switches 335 and 336 serve to c1ose the switches, thus energizing the solenoids 284 and 294, respectively, to shift the valves 280 and 290, respectively, to cut 01T exhaust of fluid from the cylinders 139 and 159, respectively, thus stopping the indexing movement of the wheel heads 138 and 158 to locate the grinding whee1s 56 and 51, respectively, in positions opposite the crankpins 58a and 59a for a grind.ing operation.

After the crankpins 58a and 56a have been ground and it is desired to again index the grinding wheels 56 and 51 for grinding the next pair of pins on the shaft, the indexing movement of the glinding Whels rnay be initiated by aotuating either the push button switch 340 or the push button switch 341. Actuation of either the push button 348 or 341 serves to break the circuit, deenergizing the solenoids 294 and 294, thus releasing the compression of the springs 282 and 292 to return the va1ves 280 and 290, respectively, to the positions illustrated in Fig. 4 so that fiuid may exhaust from the cylinders 139 and 159, respectively, thereby permitting a further longitudinal indexing movement 01 the grinding wheels 56 and 51.

A pair 0f push button switches 345 and 346 are provided for rendering the valves 280 and 290 and 250 operative or inoperative when desired. When it is desired to make valves 280, 290 and 250 inoperative, both of the switches 345 and 346 are opened. The opening of the push button switch 345 serveg to break the electric circuit through the push button switches 340 and 341. The opening of the push button switch 346 breaks a circuit rendering the circuits controlling the valVe 250, by the lirnit switches 150, I51, 152, 110, 111 and 113 inoperative, thus cutting off electric current to the solenoid 252.

The operation of the improved crankpin grindi.ng machine will be readily appamnt from the fomgoing disclosure. The push button switches 188, 236 and 259 are closed to Start the grinding wheel driving motor 180, to Start the work drive motor 40, and to start the fluid pump driving motor 261. A crankshaft 25 is then placed in position With its opposite ends supported in the pot chucks 23 and 24, after which the main control lever 108 is moved forward toward the operator to shift the main control valve 99 to initiate an infeeding movement of the grinding wheels 56 and 51. The shifting of the main nontro1 va1ve 99 first opens the fluid confined within the cyiinders 26 and 3I to the exhaust, thus reieasing the compression of the springs to clamp the opposite ends of the crankshaft 25 in position on the pot Chucks 23 and 24. Fluid next passes to the cyiinder 85 to initiate the forvvard feeding movement of the grinding wheels ES and 51 and at the same time passes through the pipe 325 to shiit the by-pass valve 328 which prevents passage of fluid to the Whl head indexing cy1- inders 139 and I59 during the infeeding movement. After the forward movement of the grinding wheels 55 and 57 has losen initiated, the control vaive 99 admits fiuid under pressure to the steadyrest cylinders l99 and 22 m move the steadyrest frames 195 and 2m, respectiveiy, upwardly into an operative position so that the w-ork steadying shoes engage and steady the crankpins 58 and 59 during a grinding operation.

After the crankpins 58 and 553 have beetn ground 110 the desired and predetermined size the control lever 133 is moved rearwardly to stop the rotation cf the work, to cause a rearward movement of the grinding whee1s 55 and 57, and also t-o unclamp the pot chucks 23 and 24 so that the crankshaft 25 may be rotarily indexed to present the crankpins 58a and 5@a With their axes in aiignment With the axes of rotation of the pot chucks 2-3 anci 2-2. During the rearvvard shifting movement of the main cont-rol valvs 95, fiuid under pressure is admitted through the pipe 321 to shift the interlock valve 328 into the position shown in Fig. 5. In this position of the valve 3263, fiuid may pass therethrough to the wheel head indexing cylinders I3S and 159, respectively.

'Ihe index control valves 283 and 264 may then be actuated to pass fiuid linder pressure to the wheel head indexing cylinders l'39 and !59, respeotively, to shift the grinding wheels 5% and 57 relatively tovvard each other into alignment with 'the crankpins 58a and 59a, respectively. As previously explained, the index control valves 233 and 264 may be operated independently cf each other independently to contro1 the indexing movement of the wheel heads 638 and E58, respectiveiy, or, if desired, the index control valves 263 and 254 may be connected so that actuation of either serves simultaneousiy to control the admission of fluid to both of the wheel head indexing cylinders 139 and l59.

The grinding wheels 56 and 5? are stopped in operative positions aligned with the crankpins 58a anti 59a by means of the cams 331 and 333 which close the limit switches 335 and 335, respsctiveiy. 'Ihe closing of the 1imit switches 335 anti 335 ssrves to enelize the solenoids 2B and 296, respectively, to cse the va1ves 288 a:od 2%, respectiveiy. 'Ihe closing of the va1ves 23i! and 290 cuts off exhaust of fiuid from the index cylinders 139 and 55%, respectively, to stop the longitudinal indexing movement of the whee1 heads 138 and 158, respectively. The control lever Ifi3 may then be moved forward to initiate a forward feeding movement of the grinding whee1s 53 and 5'!. as in the grinding of the crankpins 58 and 59. The forward. movement cf the control lever It8 serves, as above explained, to clamp the crankshaft 25 in position to initiate a forward feeding movement of the grinding Wheels 55 and 51 to shift the -by-pass valve 323 to move the steadyrests !9 and l5 to an operative position.

During the forward feeding movement cf the grinding wheelg 56 and 57, as the grinding wheels anproaeh the crankpins, the spark spiitting de- The cycle of events in this Gase is the s2tme vices actuated by the control ievers ISS! and 493 are actuated to split the spark or equaliz the side grinding on the cornerg of the grinding wheels 5 and 5'5. The spark splitting contml levsrs l8i and 193 serve, as above explained, to cause an endWise positioning movement to the grinding wheel spindies and l'55 which support the grinding wheels 55 and 57 and serve to ;facilitate a manuai positioning of the grinding whea-vls so that each corner of the grinding vvheels grinds equaliy on the opposite cheeks adjacent to the crankpin. After the crankpins 58a am]. have been groufld to the predetermined size, control lever l&8 is moved rearwardly and the pu: 1 button switches 350 and 34H are actuatad to break the circuits to deenergize the Solenoiiis am). 234 so that the valves 255 and 290 return to the position shovvn in Fig. 4. This 1E'rovemnt serves to position the valves 289 and 283 so that a longitudinal indexing movement of the whsei heads ISS and 558 may be readily efiected.

The Whes1 heads 133 and 158 may then be indexed longitudinally tovvard each other into operative pcsitions so that the grinding wheels 55 and 5? are positioned in operative relationship With the crankpins 58b and 59b. 'Ihe contro1 lever 538 may then be shifted forward again so that the parts o-perate in the manner previousiy described to grind the crankpins 58b and 53b to the desireol and predetermined size.

After the crankpins 58b and 53b have been g1ound, the control 1ever H38 is again moved rearwardly to move the grinding wheels 55 and 57 to a rearward or inoperative position. This movement of the contro1 lever IQ8 serves to reiease the crankshaft 25 so that it may -be readily removed from the pot chucks 23 and 24 and a new crankshaft to be ground inserted thereinstead.

It Will be readi1y apparent from the foregoing disclosure that on the second crankshaft to be ground, the grinoling wheels 56 and 57 may remain in positions to first grind the crankpins 58b and 55b, after which they may be indexed away from each other to grind crankpins 58a and 553a, and iastly indexed to grind crankpins 58 and 513. This arrangement prevents undue loss of time in indexing the grinding vvhee1s 56 and 57 from one end of their indexing stroke to the other before initiatin a grinding operation 011 the next c1ankshaft.

It Will thus be seen that there has been provid:d by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment aoove set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative anal not in a limiting sense.

I claim:

1. In a crankshaft grinding machine having a base, a rotatable work support including a pair of spaced aligned work heads 011 said base, a transversely movable grinding whee1 s1ide 011 said base, a pair of spaced a1igned longitundinally mova'o1e wheel heads on said s1ide, a rotatable grinding whee1 on each of said heads, a whee1 feeding mechanism to feed said slide transversely simultaneously to move said grinding wheels into operative grinding engagement With a pair of spaced aligned crankpins to be ground, and means on said slide to index said grinding whee1 heads longitudinally relative to said slide and successively into alignment With successive pairs of pins on a crankshaft.

2. In a crankpin grinding machine having a base, a rotatable work support including a pair of spaced aligned work heads on said base, a transversely movable wheel slide on said base, a pair of spaced longitudinally movable aligned grinding wheel heads on said wheel slide, a rotatable grinding wheel on each of said heads, means including a fluid pressure piston and cylinder to feed saicl wheel slicle transversely relative to the base simultaneously to grind a pair of spaced aligned crankpins on a crankshaft, means including an independent piston and cylinder interposed between each of said wheel heads and said wheel slide independently to index seid grinding wheel heads longitudinally relative to the wheel slide successively into alignment with pairs of aligned crankpins on a crankshaft.

3. In a crankshaft grinding machine having a base, a rotatable work support including a pair of spaced aligned work heads on said base, a transversely movable grinding wheel slide on said base, a pair of spaced aligned longitudinally movable work heads on said slide, a rotatable grinding wheel on each of said heads, a fiuid pressure feeding meohanism for said slide including a piston and cylinder interposed between said slide and base to produce a simultaneous feeding movement of the wheels either toward or from seid work Support, a control valve therefor, a fluid pressure indexing mechanism for each of said wheel heads including a piston and cylinder interposed between each of the wheel heads and the slide, and a valve mechanism to control the admission of fluid under pressure simultaneously to index said grinding wheel longitudinally relative to said slide suocessively to position said grinding wheels in operative relation with pairs of aligned crankpins on a crankshaft to be ground.

4. In a grinding machine as claimed in claim 3, the combination with the parts and features therein specified, in which said valve mechanisrn comprises an independent manually operable control valve for each of the grinding wheel indexing cylinders, and fluid pressure connections between said control valves whereby said control valves may be operated either independently or simultaneously.

5. In a crankshaft grinding machine as claimed in claim 3, the cornbination With the parts and features therein specified, of an independent manually operable valve for each of the grinding wheel indexing cylinders, and fluid pressure connections between said control valves and indexing cylinders whereby said valve may independently control the longitudinal indexing movement of the grinding wheels or whereby either of said valves may control the simultaneous longitudinal indexing movement of both of said grinding wheels.

6. In a crankshaft grinding machine as claimed in claim 2, the combination with the parts and features therein specified, of a plurality of adjustable stops to determine the opposite end positions of each of said wheel heads to locate the grinding wheels relative to the crankpins to be ground, and electrically aetuated means to stop the longitudinal indexing movement of both of said grinding wheel heads when the grinding wheels move to an intermediate position to locate the grinding wheels in operative position successively to grind pairs of aligned crankpins on a crankshaft.

7. In a crankshaft grinding maohine as claimed in claim 2, the. combination With the parts and features therein specified, of a normally open shut-ofi valve in the exhaust pipe line from eacn of the grinding wheel head indexing cylinders, an independent solenoid to actuate each of said valves, and a pair of spaced normally open switohes each of Which is connected to one of said solenoids and a detent on each of said grinding wheel heads which is arranged to actuate said limit switches to energize said solenoid, so as to stop the longitudinal indexing movement of the grinding wheel heads when the grinding wheels are in operative position relative to the crankpins on a crankshaft.

8. In a orankshaft grinding machine as olairned in claim 2, the oombination with the parts and features therein specified, of a main control valve for said slide oylinder and an electrically controlled fluid pressure interlocking mechanism including a valve which is arranged to render said main control valve inoperative so that a wheel feeding movernent cannot be initiated until both of the grinding wheels are indexed longitudinally into corresponding positions relative to the crankpins to be ground.

9. In a crankpin grinding machine as claimed in claim 2, the combination with the parts and features therein speoified, of a pair of spaced hydraulically operated steadyrests to support spaoed aligned crankpins during a grinding operation, a fiuid pressure cylinder to move said steadyrests to and from an operative position, a manually operable control valve which is ar ranged to control the admission to and exhaust of fluid from the wheel slide and steadyrest cylinders, and an interlock valve which is arranged normally to admit fiuid under pressure to an end ohamber in said rnain control valve to hold it in a rearward position so as to hold the grinding wheel slide and the steadyrests in inoperative positions during the longitudinal indexing movement of the grinding wheel head.

10. In a orankpin grinding machine as claimed in claim 2, the cornbination with the parts and features therein specified, of a manually operable control valve to control the admission to and exhaust of fluid under pressure from the wheel slide cylinder, an end chamber in said control valve, an interlock valve which is arranged normally to admit fluid under pressure to said end ohamber to move and maintain the control valve in a rearward position to move and hold the wheel slide in a rearward o1 inoperative position during the longitudinal indexing movement of the grinding wheel, a solenoid to shift said interlock valve, and means including a limit switch and actuating detent interposed between the wheel slide and each of said wheel heads Whereby seid solenoid is energized When the wheel heads have been indexed to predetermined operative positions relative the crankshaft to be ground so as to shift the interlock valve, thus rendering the main control valve operative to initiate an infeeding movement of the grinding wheels.

11. In a crankpin grinding machine as claimed in claim 2, the combination with the parts and features therein specified, of a manually operable control valve to control the admission t0 and exhaust of fluid under pressure from the wheel slide cylinder, an end oharnber in said control valve, an interlock valve which is arranged normally to admit f1uid under pressure to said end chamber to move and maintain the control valve in a rearward position to move and hold the whee1 slide in a rearward o1 inoperative position during the longitudinal index ing movement of the grinding wheel, a solenoid to shift said interlock valve, and a limit'switch and actuating detent therefor interposed between each of the wheel heads and the wheel slide, said limit switches being connected in series and connected with said solenoid so that When both of the wheel heads have been indexed 110 predetermined operative positions, the solenoid may be energized to shift the interlock valve so as to exhaust fluid from the end chamber, thus rendering the manually operable main control valve operative to initiate a grinding infeed of the grinding wheels.

12. In a crankshaft grinding machine as claimed in claim 2, the combination With the parts and features therein specified of a main control valve for said slide cylinder, an interlock va1ve to control the admission of fluid under pressure to an end chamber of the main control valve, a spring normally to maintain said interlock valve in a position to admit fluid to maintain the main control valve in a rearward position so as to hold the wheel slide in a rearward or imperative position, a solenoid to shift said interlock valve, a plurality of pairs of normally closed limit switehes arranged. in two sets, each of said. pairs of switches being connected in series with said solenoid, said switches of each set being arranged in line and spaced from each other in accordance with the spacing of the crankpins to be ground, and means including a detent on each of said wheel heads for engaging and actuating successive pairs of switohes when the grinding wheels are in predetermined indexed positions relative to the orankpins to be ground so as to energize said solenoid to shift the interlock valve so that fluid may exhaust from said end chamber, thus rendering said main oontrol va1ve operative to facilitate efiecting an infeed of the grinding wheels.

FRANKLIN E. JOHNSON. 

